Answer: B. No, fluorine is always assigned an oxidation number of -1.
Explanation:
The recommended dally allowance (RDA) of selenium in your diet is 55 micrograms. how many atoms of selenium is this?
Answer: 4.19 x 10^17 atoms Se
Answer:
4.2 × 10¹⁷ atoms of Se
Explanation:
Step 1: Convert the mass to grams
We will use the conversion factor 1 g = 10⁶ μg.
55 μg × 1 g/10⁶ μg = 5.5 × 10⁻⁵ g
Step 2: Calculate the moles corresponding to 5.5 × 10⁻⁵ g of Se
The molar mass of Se is 78.96 g/mol.
5.5 × 10⁻⁵ g × 1 mol/78.96 g = 7.0 × 10⁻⁷ mol
Step 3: Calculate the atoms in 7.0 × 10⁻⁷ moles of Se
We will use Avogadro's number: there are 6.02 × 10²³ atoms of Se in 1 mole of Se.
7.0 × 10⁻⁷ mol × 6.02 × 10²³ atom/1 mol = 4.2 × 10¹⁷ atom
For the following word equations, write it as a chemical equation, then balance it.
a) potassium + oxygen gas ------ potassium oxide
4K+O2-----------2K2O
If 0.654 g of oxygen dissolves in 1.5 L of water at 1.65 atm, at what pressure (in atm) would you be able to dissolve 1.35 g in the same amount of water?
Explanation:
dylalove464
06/11/2020
Hello,
In this case, we first compute the moles of oxygen in 0.654 g and 1.35 g by using its molar mass (32 g/mol):
Then, by using the ideal gas equation at the both states, given the same both temperature and volume:
We compute the volume at the second moles:
Best regards.
Answer:
3.41
Explanation:
:)
In the bicarbonate buffering system, carbon dioxide and water join to form ___________, which dissociates into hydrogen and ________________.
In the bicarbonate buffering system, carbon dioxide and water join to form carbonic acid, which dissociates into hydrogen and bicarbonate.
A buffer solution resists the changes in acidity by combining with the hydrogen ions that were added and inactivates them. It is a solution of weak acid and its conjugate base, (carbonic acid and bicarbonate). The natural conversion of carbon dioxide into carbonic acid is slow.
Bicarbonate buffer absorbs hydrogen ions and forms carbonic acid. The total number of hydrogen ions and hence the pH of the solution does not change. Bicarbonate is consumed and carbonic acid is produced when hydrogen ions are added.
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what is the effect on the boiling point of a solution produced by an insoluble nonvolatile substance ?
Answer:
nothing
Explanation:
hope this helps ;)
____ drain pipe is used for the disposal of special liquids, such as in a chemical plant or research laboratory.
What is the atomic mass of an element that has 37 protons, 43 neutrons, and 36 electrons?
Answer:
the atomic mass of the element with 37 protons,43 neutrons and 36 electrons is 80
Which is one way that topographic maps are different from other maps?
Answer:
The answer is A. Unlike other maps, topographic maps indicate man-made and natural landforms.
Explanation: Took the test and got 100% Edg. 2020
Answer:
A)Unlike other maps, topographic maps indicate man-made and natural landforms.
Explanation:
why do we not know what was on the far side of the moon until 1960's
Answer:
Like Earth, it gets plenty of sunlight. We don’t see the far side because “the moon is tidally locked to the Earth,” said John Keller, deputy project scientist for NASA’s Lunar Reconnaissance Orbiter project. “The moon does rotate, but it rotates at the same speed that it rotates around the Earth.”
Explanation:
Complete the following fission reactions: 235U+n + 128 Sb + 101 Nb+ 7n 244 *Pa+n → 10275 + 1315b + 121 Incorrect 238U+n → 99Kr+ 129 Ba + 11n 238U +n + 101 Rb + 130 Cs + 8n Incorrect Incorrect
The complete fission reactions are :
235U + n → 244Pa + 10275 + 1315b + 121n
238U + n → 99Kr + 129Ba + 11n
238U + n → 101Rb + 130Cs + 8n
The provided incomplete fission reactions can be completed as follows:
1)235U + n → 244Pa + 99Kr + 2n
In this fission reaction, uranium-235 (235U) is bombarded with a neutron (n) resulting in the formation of protactinium-244 (244Pa), krypton-99 (99Kr), and two additional neutrons (2n).
2)238U + n → 101Rb + 130Cs + 7n
In this fission reaction, uranium-238 (238U) reacts with a neutron (n) leading to the production of rubidium-101 (101Rb), cesium-130 (130Cs), and seven additional neutrons (7n).
It's important to note that fission reactions can produce a variety of isotopes and products depending on the specific isotopes involved and the conditions of the reaction. The reactions mentioned above represent simplified versions of the fission process and may not encompass all possible products or isotopes formed.
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methyl red has a pka of 5.0 and is red in its acid form and yellow in its basic form. if several drops of this indicator are placed in a 25.0-ml sample of 0.100 m hcl, what color will the solution appear? if 0.100 m naoh is slowly added to the hcl sample, in what ph range will the indicator change color?
The pKa value of methyl red is 5.
Consequently, it exhibits a colour change range of +/-1 pH unit between its pKa value of 4 and 6.
The indicator dye methyl red, commonly known as C.I. Acid Red 2, turns red in acidic solutions. It is a crystalline powder that is a deep red azo dye. Methyl red is a pH indicator with a pKa of 5.1; it is red at pH values below 4.4, yellow at pH values over 6.2, and orange at pH values in the middle.
An indicator dye called methyl red becomes red in acidic solutions. It is a pH indicator, becoming orange between pH 4.4 and 6.2 and yellow beyond pH 6.4. In microbiology, the Voges-Proskauer test is used to find bacteria that digest glucose with mixed acids to form stable acids.
Methyl red is an azo dye made of benzoic acid and a 4-[(dimethylamino)phenyl]diazenyl group at position 2. It functions as a dye. It is a tertiary amino molecule, a monocarboxylic acid, and a member of the azobenzene family.
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Which of the following is not a property of gases?
(4 Points)
are fluids
have low density
have a definite volume that doesn't vary from containers
gases are compresible
Which of the following is NOT evidence that whales and dolphins changed over time and once lived on land?
a. They have lungs
b. They have arm bones that look like those bones of land qwelling organisms.
c. They have small hairs.
d. They do not have hair.
Answer:
Am not so sure but I think that your ans is a
Answer:
D.
Explanation:
Because that's what every mammal has that lives on land. (Whales and dolphins are mammals)
a student mixes 31.0 ml of 3.06 m pb(no3)2(aq) with 20.0 ml of 0.00187 m na2so4(aq) . how many moles of pbso4(s) precipitate from the resulting solution? the sp of pbso4(s) is 2.5×10−8 .
The number of moles of PbSO₄(s) precipitated from the resulting solution would be 0.0141 moles.
A precipitation reaction will take place in which the Na₂SO₄(aq) and Pb(NO₃)₂(aq) will react and form PbSO₄(s) solid and NaNO₃(aq).
This is the balanced chemical reaction that takes place:Na₂SO₄(aq) + Pb(NO₃)₂(aq) → PbSO₄(s) + 2NaNO₃(aq)
We first need to determine the number of moles of Na₂SO₄(aq) that is available:0.0200 L × 0.00187 mol/L = 3.74 × 10⁻⁵ mol Na₂SO₄(aq)
Since the reaction has a 1:1 molar ratio between Na₂SO₄(aq) and PbSO₄(s), the number of moles of PbSO₄(s) that will form will be the same.
Therefore, 3.74 × 10⁻⁵ mol PbSO₄(s) will form.In order to calculate the mass of PbSO₄(s) that will precipitate out, we can use the formula:m = n × MM
where m = mass in grams, n = number of moles, and MM = molar mass of PbSO₄The molar mass of PbSO₄ is:1 Pb + 1 S + 4 O = 207.2 g/molSo, mass of PbSO₄(s) = 0.00775 g
We can use the solubility product constant (Ksp) to determine if all of the PbSO₄(s) will precipitate out.Ksp = [Pb²⁺][SO₄²⁻] = 2.5 × 10⁻⁸[Pb²⁺] = [SO₄²⁻] = xMoles of Pb²⁺ and SO₄²⁻ = 0.0141 mol
The molarity of PbSO₄(s) is thus:0.0141 mol ÷ 0.051 L = 0.276 M
This is greater than the Ksp of 2.5 × 10⁻⁸, so not all of the PbSO₄(s) will precipitate out.
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Calculate [NO3-] if 125 mL of 0.35 M NaNO3 is mixed with 450 mL of 1.1 M Mg(NO3)2. Please include some of your work as best as you can in the answer for full marks.
Answer: 1.76 M
Explanation:
To calculate the number of moles for given molarity, we use the equation:
\(\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}\) .....(1)
Molarity of \(NaNO_3\) solution = 0.35 M
Volume of solution = 125 mL
Putting values in equation 1, we get:
a) \(0.35M=\frac{\text{Moles of}NaNO_3\times 1000}{125ml}\\\\\text{Moles of }NaNO_3=\frac{0.35mol/L\times 125}{1000}=0.044mol\)
1 mole of \(NaNO_3\) contains = 1 mol of \(NO_3^-\)
Thus \(0.044mol\) of \(NaNO_3\) contain= \(\frac{1}{1}\times 0.044=0.044\) mol of \(NO_3^-\)
b) \(1.1M=\frac{\text{Moles of}Mg(NO_3)_2\times 1000}{450ml}\\\\\text{Moles of }Mg(NO_3)_2=\frac{1.1mol/L\times 450}{1000}=0.495mol\)
1 mole of \(Mg(NO_3)_2\) contains = 2 mol of \(NO_3^-\)
Thus \(0.495mol\) of \(Mg(NO_3)_2\) contain= \(\frac{2}{1}\times 0.495=0.99\) mol of \(NO_3^-\)
Total \([NO_3^-]=\frac {\text {total moles}}{\text {total volume}}=\frac{0.044+0.99}{0.575L}=1.76M\)
Thus \([NO_3^-\) after mixing is 1.76 M
Mg + 2HCl → MgCl2 + H2
How many grams of Mg is needed to produce 100 g of H2?
H2
n=m÷Mr
n=100×2
n=200 moles
Mole ratio
Mg : H2
1 : 1
x : 200
cross multiply= x=200
Mg
make m the subject
m=n×Mr
m=200×24.305
m=4861 g
What are the coefficients of the compounds after balancing the following equation and what type of reaction is this?
__Fe(s) + __Cl2(g) → __FeCl3(s)
The coefficient of Fe would be 2, the coefficient of Cl2 would be 3, while the coefficient of FeCl2 would be 2.
The balanced equation of the reaction would be as follows:
\(2Fe(S) + 3Cl_2 ---> 2FeCl_3(S)\)
Thus, the coefficients of Fe, Cl2, and FeCl3 respectively would be 2, 3, and 2.
In other words, 2 moles of Fe require 3 moles of Cl2 to produce 2 moles of FeCl3 in a complete reaction.
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what is true about the hydration process?
Water serves as the solvent in the solvation process known as hydration. In order to hydrate, solvent molecules must be separated and combined with solution's ions. In general, the process is exothermic.
Explain about the hydration process?When a mineral interacts with water, hydration occurs, which is a type of chemical weathering, the chemical bonds of a mineral are altered. The mineral anhydrite's reaction with groundwater is one instance of hydration. Anhydrite is changed into gypsum, which is one of the prevalent minerals on Earth, by the presence of water.For this reason, it's crucial to comprehend the three essential measures of remaining hydrated. They include drinking enough fluids, being aware of the indications of dehydration, and knowing when to modify your fluid intake in response to temperature and activity levels.Thus, the correct statement about hydration process are-
Water serves as the solvent in the solvation process known as hydration. In order to hydrate, solvent molecules must be separated and combined with solution's ions. In general, the process is exothermic.To know more about the hydration process, here
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density of a piece of wood that has a measurement of 24 cm3 and 768 g
Answer:
The answer is 32 g/cm³Explanation:
The density of a substance can be found by using the formula
\(density = \frac{mass}{volume} \\\)
From the question
mass = 768 g
volume = 24 cm³
We have
\(density = \frac{768}{24} \\ \)
We have the final answer as
32 g/cm³Hope this helps you
Answer:
The density of wood is 32 g/cm³.
Explanation:
Given data:
Mass of wood = 768 g
Volume of wood = 24 cm³
Density of wood = ?
Solution:
Density is equal to the mass divided by its volume.
Formula:
d = m/v
d = density
m = mass
v = volume
d = 768 g/ 24 cm³
d = 32 g/cm³
The density of wood is 32 g/cm³.
A gas occupies 900.0 mL at a temperature of 27.0°C. What is the volume if the temperature
A gas occupies 900.0 mL at a temperature of 27.0°C. What is the volume if the temperature is 105°C ?
Explanation:
\( \frac{V _{1} }{T _{1}} = \frac{V _{2} }{T _{2}} \\ \frac{(900)}{(27 + 273)} = \frac{V _{2}}{(105 + 273)} \\ V _{2} = \frac{340200}{300} \\ V _{2} = 1134 \: ml\)
Title:
Hi! 1 am
and I am made of ice. I
experienced (conduction, convection or radiation) in the form of (a hot sidewalk, a pot of water on the stove, the sun) [Make sure these match] I turned into liquid water and when I did, my particles changed by
_. (describe how the
speed, distance between, and the arrangement of the particles changed)
Then I turned into a gas and when that happened, my particles changed by
_ (describe how the
speed, distance between, and the arrangement of the particles changed)
The end.
As you transitioned from a solid to liquid to gas, the speed of your particles increased, distance between them grew and their arrangement became more disordered.
How did the speed, distance between and the arrangement of the particles changed?If you were placed on a hot sidewalk, you would experience conduction as the heat transferred from surface to your body.
As a result, you would turn into liquid water, and particles in your structure would begin to move faster, increase distance between them, and become more disordered. This is because the added heat increases the energy in particles, causing them to break away from their frozen state and become more fluid.
If you were exposed to the sun or another heat source, you would experience radiation as energy in form of electromagnetic waves traveled through space and heated your body.
And as a result, you would turn into gas and particles in your structure would increase in speed, become more spaced apart, and become even more disordered. This is because additional energy from heat causes particles to move around more rapidly, leading to breakdown of any remaining structure.
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Why did the changes you made result in more energy storage molecules?
2. When two oppositely charged particles are brought near each other, they produce a torceted the stone
shows the force around two changed particles
Which force do the arrows represent?
A an unbalanced force
B. a frictional force
C.an electrical force
D.a gravitational force
Answer:
A
Explanation:
An unbalanced force is your answer.
A service station has 72 octane and 84 octane gasoline. How many liters of each gasoline should be mixed to provide 12 liters of 82 octane gasoline for a chemistry experiment?
2 liters of 72 octane gasoline should be mixed with (12 - 2) = 10 liters of 84 octane gasoline to obtain 12 liters of 82 octane gasoline.
Let's assume x liters of 72 octane gasoline are mixed with (12 - x) liters of 84 octane gasoline to obtain 12 liters of 82 octane gasoline.
To find the solution, we can set up an equation based on the octane content: (72x + 84(12 - x)) / 12 = 82
Now, let's solve for x:
72x + 84(12 - x) = 82 * 12
72x + 1008 - 84x = 984
-12x = 984 - 1008
-12x = -24
x = (-24) / (-12)
x = 2
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Write the molecular formulas of alkane,alkene with one double bond, alkene with two double bonds,Cycloalkane and Cycloalkenenwith no substituents comprising six carbons.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, chemical formula can be shown as below.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.
Compound chemical formula
alkane CnH2n+2
alkene with one double bond CH\(_2\)=CH\(_2\)
alkene with two double bond CH\(_2\)=c=CH\(_2\)
cycloalkane C\(_6\)H\(_{12}\)
Therefore, chemical formula can be shown as above.
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Question 1 (1 point)
How many atoms are in 223 g of cesium?
Answer : The correct option is (b) \(1.01\times 10^{24}\)
Explanation : Given,
Mass of cesium = 223 g
Molar mass of cesium = 133 g/mole
First we have to calculate the moles of cesium.
\(\text{Moles of cesium}=\frac{\text{Given mass cesium}}{\text{Molar mass cesium}}\)
Now putting all the given values in this formula, we get:
\(\text{Moles of cesium}=\frac{223g}{133g/mol}=1.67mol\)
Now we have to calculate the number of atoms of cesium.
As, 1 mole of cesium contains \(6.022\times 10^{23}\) atoms of cesium
So, 1.67 mole of cesium contains \(1.67\times 6.022\times 10^{23}=1.01\times 10^{24}\) atoms of cesium
Therefore, the number of atoms of cesium are \(1.01\times 10^{24}\)
What happens when a base dissolves?
O A. It increases the concentration of OH in solution.
O B. It increases the concentration of Hi in solution.
O C. It is no longer dangerous.
O D. It adds oxygen to the solution.
Answer:
A. It increases the concentration of OH in solution.
Explanation:
Answer:
B. It increases the concentration of Hi in solution.
Explanation:
A.p.e.x
PLEASE HELP ME ASAPPPPPPPP!!!!!!!!! PLEASEEEEEEEEEEEEEEEEEEE
Calculate the number of grams in 50 molecules of methane (CH4). Use as molar masses
for H= 1.008 g/mol, and for C= 12.011 g/mol.
Answer:
3.1167
Explanation:
Find the molar mass of CH4 and divide the 50 grams by the molar mass
A radioactive substance decreases by 65% each hour. Find the hourly decay factor. The hourly decay factor is__
A radioactive substance decreases by 65% each hour. Find the hourly decay factor. The hourly decay factor is 0.35.
Chemicals in the class of radionuclides (also known as radioactive materials) have unstable atomic nuclei. They become stable by undergoing modifications in the nucleus (spontaneous fission, alpha particle emission, neutron conversion to protons, or the opposite).
A radioactive atom will naturally emit radiation in the form of energy or particles in order to transition into a more stable state. The difference between radioactive material and the radiation it emits must be made.
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can the element oxygen form a molecule O² . interpret why so
Answer:
Yes, it can
Find the explanation below
Explanation:
A molecule is a substance made up of more than one atom. Most times, the individual atoms of elements are UNSTABLE, hence, their atoms get chemically bonded to one another to form a MOLECULE.
Oxygen is an element denoted by the symbol O. Oxygen is made up of atoms that becomes chemically joined together via covalent bonds i.e each atom of oxygen shares their valence electrons, to form OXYGEN MOLECULE (O2). Oxygen molecule is referred to as a diatomic molecule because it is made up of two of the same atoms.